One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,8)(4,6)(5,7)(9,10,15,12)(11,16,13,17)(14,18,22,20)(19,23,21,24)(25,26)(27,29)(28,32)(30,31)(33,34)(35,39)(36,37)(38,40)(2,4)(7,8)(9,11)(10,16)(12,17)(13,15)(14,19)(18,23)(20,24)(21,22)(25,27,30,34)(26,29,31,33)(28,36,38,35)(32,37,40,39)(1,3,6,5)(2,7,4,8)(11,13)(16,17)(19,21)(23,24)(26,31)(27,34)(32,40)(35,36)(1,2,6,4)(3,7,5,8)(9,12,15,10)(11,17,13,16)(14,18,22,20)(19,23,21,24)(25,28)(26,32)(27,35)(29,39)(30,38)(31,40)(33,37)(34,36)(1,4,6,2)(3,7,5,8)(9,13,15,11)(10,17,12,16)(14,21,22,19)(18,24,20,23)(25,27)(26,33)(28,35)(29,31)(30,34)(32,37)(36,38)(39,40)(1,5,6,3)(2,7,4,8)(9,14,15,22)(10,18,12,20)(11,19,13,21)(16,23,17,24)(25,29,30,33)(26,27,31,34)(28,37,38,39)(32,36,40,35)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.